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07:04
Effective Isolation of Functional Islets from Neonatal Mouse Pancreas
Published on: January 6, 2017
Secretion from islets and single islet cells following cryopreservation
J R Lakey1, C A Aspinwall, T J Cavanagh
1Surgical-Medical Research Institute, University of Alberta, Edmonton, Canada. jonathan.lakey@ualberta.ca
Cell Transplantation
|March 4, 2000
Summary
Cryopreservation of canine islets and beta-cells effectively preserves insulin secretion function. Frozen-then-thawed islets and beta-cells demonstrate comparable insulin release and exocytosis frequency to non-frozen controls.
Area of Science:
- Endocrinology and Metabolism
- Cell Biology
- Cryobiology
Background:
- Cryopreservation of pancreatic islets enables donor islet banking, facilitating pooling and testing.
- Previous research indicates cryopreservation and thawing can reduce islet mass and function.
- Assessing the functional integrity of cryopreserved islets and beta-cells is crucial for therapeutic applications.
Purpose of the Study:
- To quantitatively compare insulin secretion from cultured non-frozen and cryopreserved (frozen-thawed) canine islets and beta-cells.
- To evaluate the functional recovery of beta-cells post-cryopreservation and thawing.
Main Methods:
- Canine islets were isolated and cultured; a portion was cryopreserved using dimethyl sulfoxide (DMSO) and slow cooling, then rapidly thawed.
- Insulin secretion was assessed in vitro from cultured non-frozen and frozen-thawed islets.
- Single beta-cell exocytosis events were monitored in real-time using amperometry with carbon fiber microelectrodes following chemical stimulation (tolbutamide).
Main Results:
- Islet recovery after cryopreservation and culture was 81.5% compared to pre-cryopreservation counts.
- In vitro islet function, measured by stimulation index, was statistically equivalent between non-frozen (12.4) and frozen-thawed (10.4) islets.
- Single beta-cell analysis revealed comparable frequencies of exocytosis events (non-frozen: 7.0 events; frozen-thawed: 6.0 events) and equivalent insulin release per event.
Conclusions:
- Cryopreservation and thawing protocols maintain the functional capacity of canine islets and beta-cells.
- Frozen-thawed beta-cells exhibit comparable insulin secretion levels and exocytosis frequencies to non-frozen controls.
- Cryopreserved beta-cells retain responsiveness to secretagogues like tolbutamide, supporting their potential therapeutic viability.
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